1. Chapter 21 Nucleic Acids and Protein Synthesis
21.9 Recombinant DNA

2. Recombinant DNA In recombinant DNA,
a DNA fragment from one organism is combined with DNA in another
restriction enzymes are used to cleave a gene from a foreign DNA and open DNA plasmids in Eschericia coli
DNA fragments are mixed with the plasmids in E. coli and the ends are joined by ligase
the new gene in the altered DNA produces protein

3. Recombinant DNA (continued)

4. Products of Recombinant DNA

5. DNA Fingerprinting In DNA fingerprinting (Southern transfer):
restriction enzymes cut a DNA sample into smaller fragments (RFLPs)
the fragments are sorted by size
a radioactive isotope that adheres to certain base sequences in the fragments produces a pattern on X-ray film, which is the “fingerprint”
the “fingerprint” is unique to each individual DNA

6. Polymerase Chain Reaction
A polymerase chain reaction (PCR):
produces multiple copies of a DNA in a short time
separates the sample DNA strands by heating
mixes the separated strands with enzymes and nucleotides to form complementary strands
is repeated many times to produce a large sample of the DNA

7. Polymerase Chain Reaction (continued)